Bowel malabsorption

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• 作者：L. Crocella ; R. Rocca ; M. Daperno ; M. Migliardi ; A. Pera
• 关键词：Bowel malabsorption ; Malabsorption and diagnosis ; Videocapsule endoscopy ; Endoscopy and histology
• 刊名：Immuno-analyse Biologie Spécialisée
• 出版年：2008
• 出版时间：August 2008
• 年：2008
• 卷：23
• 期：4
• 页码：224-229
• 全文大小：940 K

文摘

Summary

Definition

Pathological alteration regarding nutrients transport, digestion or absorption through small bowel's wall. The consequences are diarrhea, steatorrhea and malnutrition. Different situations can produce malabsorption: alteration of nutrients absorption due to a wide spectrum of damage of small bowel's mucosa and pathological change of nutrients’ digestive phase. According to different pathological mechanism, some malabsorption diseases impair the assimilation of many nutrients and vitamins whereas others are more selective.

Pathophysiology

Three principal mechanisms are involved: premucosal, mucosal and postmucosal. Premucosal mechanisms generally produce a maldigestion (a digestive phase alteration in the intestinal lumen). Mucosal mechanisms (with a reduction of absorption through the small bowel's wall) and postmucosal mechanisms (with an alteration of nutrients transport through lymphatic vessels) produce a real malabsorption. Different diseases are involved in maldigestion and malabsorption: bowel diseases (celiac disease, Crohn, lymphomas, eosinophilic gastroenteritis, intestinal infections), gastric diseases (gastric atrophy, gastrectomy), pancreatic diseases (chronic pancreatitis, pancreatic neoplasms), hepatic diseases (cirrhosis, PSC, PBC, biliary tract neoplasms), neuroendocrine tumors and systemic diseases (LES, sclerodermas).

Clinical symptoms

Chronic diarrhea, abdominal pain and bloating, steatorrhea, anemia, weight-loss, osteopathy, osteoporosis, paraesthesias, tetanic crisis, stomatitis, glossitis.

Diagnosis

Evaluation of nutrients deficit through blood-tests, EMA and tTG-Ab, IgG dosage (to diagnose a common variable immunodeficiency). More specific tests are: fecal fats dosage and secretin and CCK pancreatic tests. Endoscopy with gastric, duodenal and small bowel biopsy play a very important role (celiac disease, Crohn, lymphomas, Whipple's disease, amiloidosis). Videocapsule enteroscopy is very useful to identify intestinal mucosa alterations in small bowel. Barium meal with small bowel follow-through, small bowel double contrast enema can give important information particularly when there is a doubt of ileal Crohn's disease. Hydrogen breath tests (lactose, sorbitol, glucose), by hydrogen expiration measurement, are useful to diagnose intestinal bacterial overgrowth or lactase deficiency.